Elevator control system



Jan. 12, 1943. R. A `wAlTE ET AL 2,308,221

' ELEVATOR CONTROL SYSTEM Filed Aug. 3l, v 1942 2 Sheets-Sheet l Al R1 EHI ATTORNEY Patented Jan. 12, 1943 ELE-VATOR CONTROL SYSTEM Raymond Alonzo Waite, Yonkers, and Lee Irwin Davis, New York, N. Y., assignors to Otis E1evator Company, New York, N. Y., a corporation of New Jersey Application August 31, 1942, Serial No. 456,830

(Cl. IS7- 29) 10 Claims.

The invention relates to push button control systems for elevators.

There are various types of elevator installations, in which the operation of the car is controlled by push buttons for the various iloors, where it is desirable that exclusive control of the car be given to the first push button pressed. It sometimes happens however that after a push button is pressed to send the car to the corresponding floor, the person pressing the button desires to change the destination. This is especially true in the case of parking garage elevators in which the operation of the car is controlled solely by push buttons in the car. The attendant in the car may not press the proper button initially or may be advised by signal to change his destination. In known push button control systems of these types, it is necessary to press a stop button to bring the car to a stop before another push button may be .effectively pressed to change the destination of the car.

It is the object of the present invention to provide a push button control system for elevators in which the destination of the elevator car may be changed simply by pressing the button for the new destination.

In accordance with the invention, when a push button is pressed to change the destination of the car, it registers a call for the floor for which the button is provided and cancels the call registered by the initially pressed button. If the button pressed is for a iloor toward which the car is travelling, the car continues to and stops at that floor regardless of whether the floor is beyond or short of the original destination. If the button pressed is for a floor behind the car, the car is brought to a stop, reversed and brought to and stopped at that floor. The previously registered -call is not answered.

Features and advantages of the invention will become apparent from the above statements, the description which follows and appended claims.

In the drawings:

Figure 1 is a simplied wiring diagram in across-the-line form of an elevator control system embodying the invention; and

Figure 1s is a key diagram for Figure 1 showing the electromagnetic switches in spindle form with the contacts and coils arranged on the spindles in horizontal alignment with the corresponding contacts and coils in the wiring diagram.

The invention will be described as applied to an elevator installation in which push buttons are provided only in the elevator car. For convenience, the control system is considerably simplified. Referring to the drawings, push button control circuits for only four floors are illustrated. A push button is provided in the car for each of the iloors. These buttons are designated PB and in accordance with the iloors for which they are provided, The push buttons operate floor relays to register the calls. 'I'he floor relays are designated FR and also in accordance with the floors for which they are provided. A self-holding circuit is provided for each floor relay to enable the operating push button to be released.

In the control system illustrated, a floor controller is utilized in conjunction with the push buttons and floor relays to control the operation of the car. A floor controller of the form disclosed inthe patent to Dunn No. 2,032,475, granted March 3, 1936, may be utilized, the particular parts of such floor controller employed in the system illustrated having been diagrammatically indicated in the wiring diagram. The floor relays act through direction mechanism of the iioor controller to control the direction of travel of the elevator car. This mechanism comprises a plurality of stationary direction switches, one for each iloor, designated DRI, DR2, DR3 and DR4 for the first, second, third and fourth floors respectively, and a directionl cam of three sections designated CU, CN and CD. The iioor relays also act to render effective stationary contacts on the oor controller which are engaged by brushes to initiate the stopping operation. The stationary contacts are designated Sl, S2, S3 and S4 for the rst, second, third and fourth floors respectively, while the cooperating brushes are designated BU and BD, the iirst being for up car travel and the second for down car travel. The pawl magnet of the floor controller is designated PM and the contacts operated thereby PMI.

The electromagnetic switches employed in the control system have been designated as follows:

A Up reversing switch AA Up reversing switch relay B Down reversing switch BB Down reversing switch relay C Potential switch CB Car button relay CC Destination changing relay FF Pawl magnet relay L Accelerating switch M Direction holding relay MB Call cancelling relay T rIime relay X Call registering relay A polyphase alternating current source of supply has been illustrated, the supply lines being designated I, II and III. KS is a triple-pole knife switch for connecting the system to the supply mains. A rectier REI is utilized to provide direct current derived from the alternating current supply mains for the release coil of the electro-mechanical brake BR.

The hoisting motor is illustrated as a polyphase alternating current squirrel cage induction motor. The stator windings of the motor are designated EMI, EMZ and EM3 while the rotor is designated EMR. RI, R2 and R3 are resistances in circuit with the stator windings of the hoisting motor. The gate contacts are designated GS, while the door contacts, closed only when the respective doors are closed and locked are designated as a whole as DS. The car gate is manually operated and must be closed upon entering or leaving the car. The doors are provided with means to return them to closed position when released. The locking of the door for a floor at which the car is standing is effected by means of a retiring cam in the usual manner. This cam is operated by a retiring cam magnet designated CM. R4, R5, R6, RI, R8, R9 and RIO are control resistances while IND is an inductance. SB designates the emergency stop button in the elevator car. ULI and UL2 are the normal up limit switches, DLI and DL2 are the normal down limit switches, and UL3 and DL3 are the nal limit switches. LI and L3 are feed lines from the alternating current supply mains for the control switches.

The system is illustrated for the condition with the car standing at the second oor. Assume that the car is provided with an attendant and that he desires to send the car to the rst iloor and presses push button IPS. This completes a circuit from feed line LI through limit switches ULS and DL3, contacts MBI, coil of car button relay CB, push button IPB, coil of rst floor relay IFR, to feed line L3. Relay CB initiates a sequence of operation of switches M, MB and CC, the purpose of which is served in changing the destination. As this operation is not now involved, this sequence will be described later. Relay IFR operates to engage contacts IFRZ to establish a self-holding circuit through contacts XI and resistance R4, these floor relay contacts also rendering first oor floor controller stationary contact SI alive. The floor relay also engages contacts IFRI which, with contacts CBI of car button relay CB in engagement, completes a circuit from feed line LI through contacts CBI,

IFRI, direction switch DRI, cam section CD, coil of down reversing switch relay BB, contacts AAS, limit switch DLI and stop button SB, to feed line L3, causing operation of relay BB.

The down auxiliary reversing switch relay BB, upon operation, separates interlock contacts BBI in circuit with the coil of relay AA, engages contacts BB3 to render down brush BD alive, and engages contacts BB2 to by-pass contacts CBI so that the push button may be released. It also engages contacts BBS to prepare the circuit for the coil of switch C and contacts BBS to prepare the circuit for the coil of switch B. Further, it engages contacts BB4 to complete the circuit for the coil of the pawl magnet PM. The pawl magnet retracts its pawls, engaging contacts PMI to complete a circuit for the coil of potential switch C. This switch engages contacts CI and C2 in the circuit for the hoisting motor. completing the circuit for the cam magnet CM. This magnet retracts the retiring cam to lock the second floor hatchway door, engaging second floor door lock contacts DS. This completes a circuit for the coil of down reversing switch B through contacts BBS, coil of switch B, contacts A5, limit switch DL2, contacts TI, door lock contacts DS, gate contacts GS, and pawl magnet contacts PMI, causing operation of switch B.

The down reversing switch B, upon operation, separates interlock contacts B5, engages contacts B3 to by-pass contacts XI and engages contacts B4 to connect neutral cam section CN to down section CD. It also engages contacts B6, completing the circuit for the coil oi switch T which separates contacts TI to insert resistance R9 in circuit with the coil of switch B. Switch B also engages contacts BI and B2 to complete the circuit for the stator windings of the hoisting motor for a phase rotation of applied voltage for down car travel. Contacts BI also complete a circuit for rectiiier REI to cause energization of the brake release coil BR, so that the brake is released and the car started in the down direction. Contacts B2 complete a circuit for the coil of accelerating switch L which operates to short-circuit resistances RI, R2 and R3 to increase the torque of the hoisting motor for full speed operation.

As the car nears the rst floor, brush BD engages contacts SI, completing a circuit through contacts MBI and XI, resistance R4, contacts IFRZ, Contact SI, brush BD, contacts BB3 and the coil of pawl magnet relay FF. Relay FF operates to engage contacts FFI, establishing a selfholding circuit by-passing contact SI and brush BD. It also engages contacts FFS which complete a circuit for the coil of call registering relay X. Relay X operates to separate contacts XI, these contacts being by-passed however by contacts B3. Relay FF also separates contacts FFZ, breaking the circuit for the pawl magnet which releases its pawls. Upon engagement of the down pawl with the rst iloor stopping collar as the car continues its movement, contacts PMI are opened, breaking the circuit for the coils of potential switch C and down reversing switch B. These switches drop out to break the circuit for the hoisting motor and to deenergize the brake release coil, and the brake is applied to bring the carto a stop at the rst floor. Switch B in dropping out also separates contacts B4 to break the circuit for the coil of down reversing switch relay BB. Also ccntacts B3 separate to break the holding circuit for the coil of the first oor relay IFR and the circuit for the coil of pawl magnet relay FF. Relay FF separates contacts FFS to deenergize relay X. The dropping out of potential switch C also breaks the circuit for the coil of cam magnet CM. This magnet releases the retiring cam to unlock the rst floor hatchway door.

Assume that it is desired to send the car from the rst iioor to the third iloor. The third licor car button 3PB is pressed, causing operation of third floor relay SFR. This relay engages contacts BFRI, completing a circuit for the coil of up reversing switch relay AA. This relay acts to cause operation of switches C and A to start the car in the up direction. It is not believed that it is necessary to describe this operation in detail in view of the previous description of starting the car in the down direction. As the car nears the third floor up brush BU engages contacts S3 to cause deenergization of the pawl magnet. Thus, as the car reaches the third floor,

the up pawl causes opening of contacts PMI to break the circuit for the coils of switches C and A, thus causing the car to be brought to a stop. It is believed that this also will be understood without detailed description in view of the previous description of a stopping operation.

Assume now that the car has been started in the down direction from the fourth floor in response to the second floor push button. ZPB. Thus the second floor relay 2FR, down reversing switch relay BB, time relay T, down reversing switch B, and potential switch C are operated. Assume further that the attendant desires to change his destination from the second to the rst iioor. To do so, he simply presses the first floor car button IPB which causes operation of the iirst floor relay IFR and car button relay CB. Relay CB engages contacts CB2, completing a circuit for the coil of direction holding relay M. Relay M engages contacts MI and M2, the latter by-passing contacts ZFRI in the circuit for the coil of down reversing switch relay BB. Relay M also engages contacts M3 to establish a selfholding circuit and engages contacts M4 to complete a circuit for the coil of call cancelling relay MB. Relay MB separates contacts MBI breaking the energizing and holding circuits for the floor relay coils, causing the dropping out of both the second and rst floor relays ZFR and IFR and of relay CB. It also engages contacts MB3 to complete a circuit for the coil of destination changing relay CC. This relay is delayed slightly in operation by inductance IND to insure the dropping out of the floor relays. Upon operation it engages contacts CCI which reestablishes the circuit for the coil of relay CB and the coil of first floor relay IFR through push button IPB. Relay CC also separates contacts CC2, these contacts being arranged not to separate until after contacts CCI engage. Upon separation of contacts CO2, the coil of relay M is deenergized. Relay M upon dropping out separates contacts M2 but contacts IFRI maintain the circuit for the coil of dov/n reversing switch relay BB. Also contacts C133, upon reengaging, establish a holding circuit for the coil of relay MB which therefore remains operated after separation of contacts M4. Upon release of push button IPB, relay CB drop-s out deenergizing relay MB which reengages contacts MBI, by-passing contacts CCI in the floor relay holding circuit. Relay MB also separates contacts MBS breaking the energizing circuit for the coil of relay CC. Relay CC is delayed in dropping out by the effect of inductance IND and discharge resistance R'I to insure the reengagement of contacts MBI before the separation of contacts CCI. Thus the rst iioor relay remains operated, causing the car to continue to the first floor instead of stopping at the second floor.

Should the attendant in the above example have desired to change his destination from the second floor to the third floor, he would press the third iioor car button 3PB. It is believed that the change over of the oor relays will be understood from the above description. Should the change over be effected before the car nears the third floor, relay FF is operated upon engagement of brush BD with contact S3 to cause stopping of the car at the third floor. Assume however that the car has passed the third floor when the third oor push button is pressed. Upon operation of relay CC to cause reoperation of the third iioor relay and to cause dropping out of relay M, the

down reversing switch relay BB is deenergized and the circuit of the coil of up reversing switch relay AA is completed through contacts CBI and 3FRI. The dropping out of relay BB breaks the circuit for the coils of potential switch C and down reversing switch B. These switches drop out to cause the stopping of the car. Also switch B separates contacts B6 to deenergize the coil of time relay T. Relay T does not drop out immediately, being delayed by the effect of discharge resistance RID. Thus resistance R9 is maintained in circuit with the coils of the reversing switches to prevent immediate operation of up reversing switch A, thereby obviating plugging of the hoisting motor. Upon dropping out of switch T, contacts TI engage to cause operation of up reversing switch A, starting the car in the up direction. Brushes BU and BD are set so that brush BU in its downward movement and brush BD in its upward movement engage the stationary contact for the iloor just passed before cam section CN leaves the direction switch for that floor. Thus, in the above example, brush BU will be in engagement with contact S3 at the time the car starts in the up direction or will engage it in the subsequent upward movement of the car to cause energization of the coil of pawl magnet relay FF and the car will be brought to a stop at the third floor and the third floor relay will be reset, as above described.

It will be seen, therefore, that by a simple arrangement of circuits, the destination of the oar may be changed simply by pressing the button for the new' destination. If the new destination is ahead of the car, the car continues running in the same direction and stops at the new destination, running past the original destination without stopping if the new destination is a oor beyond. If the new destination is behind the car, the car is brought to a stop, started in the opposite direction and stopped at the new destination. In all cases, the original call is cancelled and is not responded to.

The invention is especially applicable to garage elevators under the exclusive control of a bank of buttons within the car. It is also applicable to other systems such as dumbwaiters in which the car is controlled by one group of push buttons, for example at a dispatching station. Also, the invention may be applied to systems in which push buttons are provided at the landings as well as in the car, with the control arranged so that the destination may be changed from within the car. Also the invention may be lapplied to systems where controls for the various oors other than push buttons are employed to control the operation of the car. Other forms of motor control systems and control mechanism may be employed and the doors and/or gate may be manually or automatically operated. As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In combination; an elevator car serving a plurality of floors; a plurality of controls, one for each of said floors; means for registering calls for the respective floors in response to said controls; and means responsive, under conditions where a call is registered for a floor, to the operceiling said call and for causing operation of said rst named means to register a call for said other oor.

2. In combination; an elevator car serving a plurality of oors; a plurality of controls, one for each of said floors; means for registering calls for said floors in response to said controls; means responsive to a call that is registered for causing the car to go to the floor for which the call is registered; and means responsive, under conditions where a call is registered for a oor, to the operation of a control for another floor for cancelling said call and for causing operation of said rst named means to register a call for said other Hoor regardless of Whether said other floor is ahead oi or behind the car.

3. In combination; an elevator car serving a plurality of floors; a plurality of controls, one for each of said floors; means for registering calls for said oors in response to said controls; means responsive to the registration of a call for starting the car toward the floor for which the call is registered; means responsive, under conditions where the car has started in response to a call for a floor, to the operation of a control for a door behind the car for cancelling said call and for causing operation of said rst named means to register a call for said iioor behind; and means responsive to the change in calls for bringing the car to a stop and causing it to go in the opposite direction to said oor behind.

4. In combination; an elevator car serving a plurality of iioors; a plurality of controls, one for each of said iioors; means for registering calls for said floors in response to said controls; means responsive to the registration of a call for starting the car toward the loor for which the call is registered; means responsive, under conditions where the car has started in response to a call for a floor, to the operation of a control for another floor ahead of the car, regardless of whether such other iioor is short of or beyond the oor for which the call is registered, for cancelling said call and for causing operation of said first named means to register a call for said other iioor; and means for causing the car to continue its travel without stopping and to go to said other oor.

5. In combination; an elevator car serving a plurality of oors; a plurality of controls, one for each of said floors; means for registering calls for said floors in response to said controls; means responsive to a call that is registered for sending the car to the floor for which the call is registered; means responsive, under conditions where a call is registered for a oor, to the operation of a control for another iloor for cancelling said call and for causing operation of said call registering means to register a call for said other floor; and means for causing the car to go to said other floor in response to the new call, said last named means acting in the event the floor for which the new call is registered is ahead of the car to cause the car to continue running without stopping, regardless of whether such iioor is short of or beyond said oor for which the previous call was registered.

6. In combination; an elevator car serving a plurality of floors; a plurality of push buttons, one for each of said floors; means for registering calls for said floors in response to said push buttons; means responsive to the registration of a call for sending the car to the floor for which the call is registered; means responsive, under conditions where a call is registered for a floor, to the pressing of a push button for another oor for cancelling said call and for causing operation of said call registering means to register a call for said other floor; means operable when the new call is for a floor ahead of the car for causing the car to continue without stopping to such oor; and means operable when the new call is for a floor behind the car for causing the car to be brought to a stop and for causing operation of said second named means to send the car in the opposite direction to such floor.

7. In combination; an elevator car serving a plurality of iioors; a plurality of push buttons, one for each of said floors; a plurality of floor relays, one for each oor, responsive to the push buttons for the corresponding oors for registering calls for such floors; means responsive to the registration of a call for sending the car to the iloor for which the call is registered; and switching means responsive, under conditions where a call is registered, to the pressing of a push button for another floor for cancelling said call and for causing operation of the floor relay for said other iioor to register another call, said switching means including means for causing the car, in the event the new call is for a floor in `the direction from the car in which the car has been travelling, to continue its travel in the same direction Without stopping to said oor for which the new call is registered and, in the event said new call is for a oor in the opposite direction from the car, to reverse its travel after the change in calls has been effected and to go to the floor for which the new call is registered.

3. In combination; an elevator car serving a plurality of floors; a plurality of push buttons, one for each of said floors; a plurality of iloor relays, one for each floor, controlled by the push buttons for the corresponding floors; means for each iloor relay for retaining the oor relay upon operation in operated condition; means responsive to the operation of a floor relay for causing starting of the car toward the iioor for which the iloor relay is provided; means for causing stopping of the car at the floor for which the operated floor relay is provided; and switching means responsive, under conditions where a iioor relay is already operated, to the pressing of a push button for another floor for dropping out said operated floor relay and for causing operation of the floor relay for said other floor, said switching means including means for causing the car to continue its travel in the same direction until the change in operated oor relays has been effected, said oor relay for said other iloor acting after said change in operated floor relays has been effected to cause, in the event said other oor is in the direction from the car in which the car has been traveling, travel of the car to be maintained in the same direction and to cause, in the event said other floor is in the opposite direction from the car, stopping of the car and operation of said first named means to start the car in the opposite direction.

In combination; an elevator car serving a plurality of oors; a plurality of push buttons in the car, one for each of said floors; a plurality of iioor relays, one for each floor, controlled by the respective push buttons, each floor relay being adapted upon operation to establish a selfholding circuit; direction determining means controlled by said oor relays for causing upon operation of a oor relay starting of the car toward `the iloor for which the iioor relay is provided; means for causing stopping of the car at the iloor for which the operated floor relay is provided; and switching means responsive, under conditions where a floor relay is already operated, to the pressing of a push button for another floor for breaking the holding circuit for said operated floor relay and for causing operation of and the establishment of the holding circuit for the floor relay for said other floor, said switching means including means for controlling said direction determining means to cause the car to continue its travel in the same direction until the change in operated oor relays has been effected, said floor relay for said other floor acting after said change in operated door relays has been effected to cause, in the event said other floor is in the direction from the car in which the car has been travelling, operation of said direction determining mechanism to maintain travel of the car in the same direction and to cause, in the event said other iloor is in the opposite direction from the car, stopping of the car and operation of said direction determining mechanism to effect starting of the car in the opposite direction.

l0. In combination; an elevator car serving a plurality of floors; a plurality of push buttons in the car, one for each of said floors; a plurality of floor relays, one for each push button, each floor relay being adapted upon operation to establish a self-holding circuit; a pair of reversing switch relays, one for each direction of travel, an operated oor relay causing operation of the reversing switch relay for the direction from the car of the oor for which the floor relay is provided; means controlled by said reversing switch relays for starting the car; means for causing stopping of the car at the floor for which the operated floor relay is provided; switching means responsive, under conditions where the car is under control' of an operated door relay, to the pressing of a push button for another floor for breaking fthe holding circuit ior said operated floor relay and for causing operation ci and the establishment of the holding circuit for the floor relay for said other iloor;

and means controlled by said switching means for causing the operated reversing switch relay to be maintained operated until the change in operated floor relays has been eiected to cause the car to continue its travel in the same direction, said operated reversing switch relay dropping out after the change in operated floor relays has been effected in the event said other ioor is in the opposite direction from said car to cause the car to be brought to a stop, said iioor relay for said other iloor, in the event said other iioor is in the direction from the car in which the car has been travelling, causing the operated reversing switch relay to be maintained operated to cause the car to continue its travel in the same direction and, in the event said other oor is in the opposite direction from the car, causing operation oi said reversing switch relay for the opposite direction to cause operation of said starting means to start the car in the opposite direction after it has been brought to a stop, and said stopping means causing stopping of the car as it arrives at said other iioor.

RAYMOND ALONZO WAITE. LEE IRWIN DAVIS. 

